1. Field of the Invention
The present invention relates to apparatuses and methods for processing data packets, and particularly to an apparatus and a method for processing Voice over Internet Protocol (VoIP) packets.
2. Description of Related Art
VoIP is a technology that allows transmission of real-time audio using an Internet Protocol (IP) network, such as the Internet. To transmit real-time audio over the IP network, audio signals are stored in a payload of one or more data packets. Such data packets are generally referred to as “VoIP packets”. Unlike a telephone network in which there is a dedicated connection and path between a source and a destination, each VoIP packet may travel on a different path from the source to the destination in the IP network, and some VoIP packets may travel faster than others. Thus, the VoIP packets transmitted over the IP network may be received out of order. To compensate for these path differences, a jitter buffer is located at the receiver for storing received VoIP packets and forwarding the audio signals stored in the payload of the VoIP packets to a listener at the rate the VoIP packets were received in the jitter buffer.
One standard protocol for packetizing the real-time audio signals for transmission over the IP network is the Real-Time Transport Protocol (RTP) (Request for Comments “RFC” 3550, July. 2003) at http://www.ietf.org/rfc/rfc3550.txt. However, the RTP only provides information for error handling, without providing functions for error handling. Thus, once network congestion occurs, the VoIP packet(s) may be lost or delayed, and the quality of the audio signals may be seriously downgraded.
Accordingly, an apparatus and method for processing VoIP packets are desired in order to overcome the above-described problems.